CN112470060A - Head-up display - Google Patents

Referring to fig. 1, the configuration of the HUD1 according to the present embodiment will be described. Fig. 1 is a schematic configuration diagram of the HUD 1. In the HUD1 of fig. 1, a

43 included in the virtual image optical system and a

44 for rotating the

43 are used as a light blocking member for opening and closing the optical path of the image light L.

As shown in fig. 1, the HUD1 is provided in the

4 of the

2. The

4 includes an instrument panel opening 7 through which the image light L emitted from the HUD1 passes. The image light L emitted from the HUD1 reaches the

3 as a projection target member through the instrument panel opening 7, is reflected by the

3, and enters the eyes of the

5. The

5 visually recognizes the

100 based on the image light L at a position forward of the

3. The member to be projected is not limited to the

3, and other members such as a combiner may be used as long as the member to be projected with the image light L is used.

The HUD1 includes a

50, a HUD control device 20 (corresponding to a main control device) and an

30 housed or attached to the

50, and a virtual image

40 configured to enlarge and project image light L emitted from the

30.

A housing opening 51, which is an exit port for the image light L, is formed in the upper surface of the

50. The housing opening 51 is covered with an antiglare shield (glare trap) 52 for preventing dust and dirt from entering the

50. The

52 is formed of a member that transmits visible light.

The

30 is configured using an LCD (Liquid Crystal Display), and operates in accordance with a control signal from the

20. More specifically, the

30 includes a

31, an illumination

32, and a

33 that displays a display object. Light emitted from the

31 passes through the

33, and image light L (see fig. 4) including a display object is emitted from the

30.

The virtual image

40 is configured such that the

41, the

42, and the

43 are arranged in this order from a position close to the

30 along the emission direction of the image light L. Further, the virtual image

40 includes a

44 configured to rotate the

43.

The

41 is a unit of at least one lens for adjusting an optical distance from the

30 to the

42.

The reflecting

42 is a mirror that reflects the optical path of the image light L emitted from the

41 toward the

43.

The

43 reflects the image light L reflected by the reflecting

42 toward the housing opening 51. The

43 is rotated by a

44.

Fig. 2 is an enlarged configuration diagram of the

44.

The

44 includes: a

44a and a

44b of the

44 a; a

45 connected to the front end of the

44b and accommodating the

43; the

46 is a bearing member for the

44 b.

As shown in fig. 1, the

44a is connected to the

20 via a

61. The

44a is driven in accordance with a control signal from the

20. When the

44a is driven, the

44b rotates, and the

45 coupled to the

44b rotates. As a result, the

43 rotates integrally with the

45.

Since the

43 rotates, the image light L can be reflected toward the

3 with its reflection angle changed. When the reflection angle of the image light L is changed, the reflection position of the image light L at the

3 is changed, and the optical path length of the image light L can be changed. Since the distance of the virtual image plane displaying the

100 changes due to the change in the optical path length, and in addition, the reflection position changes, the display height of the virtual image plane changes.

A

10 for shielding direct sunlight from entering the HUD1 is provided on the windshield-side end portion of the

4 at the instrument panel opening 7. At the

10, the

70 is disposed in a position and orientation that includes the

52 in the angle of view. The

70 is connected to the

20 by a

62, and an image captured by the

70 is output to a viewpoint detection device 700 (see fig. 4) described later. When the

20 has the function of the

700, an image is output to the

20.

The image of the

70 is used for both the viewpoint detection processing of the

5 and the incident amount monitoring processing of the direct sunlight incident on the HUD 1. Therefore, both the eyes of the

5 and the

52 need to be imaged in the image. Therefore, in the present embodiment, as shown in fig. 3, the lens of the

70 is directed toward the

52, and the light reflected by the surface of the face including the eyes of the

5 is reflected by the

3, reaches the

52, is reflected by the surface of the

52, and enters the attachment position of the lens of the

70 and the orientation (angle of view) of the lens, and is provided in the

10. The attachment position of the

70 to the

52 and the orientation of the lens are one of the features of the HUD1 of the present embodiment.

The

70 is equipped with a near-infrared

70a such as an LED that emits near-infrared light and a CMOS70b as an imaging element that detects near-infrared light to visible light. In the viewpoint detection processing, near-infrared light is used. That is, the near-infrared light generated from the near-infrared

70a mounted on the

70 reaches the face surface (face area) including the eyes of the

5 and is reflected, and the reflected near-infrared light reaches the

52 and is reflected again toward the CMOS70b, and enters the CMOS70 b. The

70 generates and outputs a face image of the

5 based on the near-infrared light image from the output from the CMOS70 b. This enables the

5 to detect the viewpoint even when the outside is dark, for example, at night, in a tunnel, or in an underground parking lot.

On the other hand, visible light is used for monitoring the amount of incident sunlight. The visible light reaching the

52 is incident from the

52 to the CMOS70 b. The

70 generates and outputs an outer surface image of the

52 based on a visible light image from the output from the CMOS70 b.

Fig. 3 is a diagram showing the angle of view of the

70.

Generally, the line of sight direction of the

5 who visually recognizes the

100 has a depression angle (for example, 1) with respect to the horizontal direction^°～5^°). Therefore, when the

5 is imaged while matching the optical axis of the

70 with the optical path of the image light L, the

5 is imaged in a head-down state, and the accuracy of detecting the coordinates of the eyes is lower than in the case where the line of sight is directed in the horizontal direction.

Therefore, in the present embodiment, as shown in fig. 3, the

70 is provided so as to match the orientation and position of the optical axis of the

70 in such a manner that the surface of the face including the eyes is imaged at an angle close to the horizontal (an angle closer to the horizontal than the case where the eyes are imaged along the optical axis of the image light L). For example, the

70 is set to an orientation in which the optical axis of the

70 is incident toward the center of the eyepoint of the

5 at an angle within an allowable range that can be regarded as horizontal with respect to the horizontal axis. This makes it possible to capture the eyes of the

5 in a direction close to the horizontal direction and output an image close to the frontal image. Therefore, the accuracy of the viewpoint detection processing in step S20, which will be described later, can be expected to be improved.

The

20 includes a 1 st ECU (electronic Control Unit) 21, a 1 st

22 connected to the 1 st ECU via a system bus, a 1

23, a light

24, a

25, a display

26, a 1 st CAN communication Unit 27 (CAN: Controller Area Network), a mirror adjustment Unit 28, and a

29. The 1 st CAN

27 is connected to the

700 via CAN. The light

24 is connected to the

31, the display

26 is connected to the

33, and the mirror adjustment unit 28 is connected to the

44 a. The 1 st ECU21 acquires the vehicle information 9 such as speed and engine speed from the 1 st CAN

27 via the CAN of the

2, and displays the display object including the vehicle information 9 as a

100.

The

700 includes a 2 nd ECU701, a

702, a 2 nd CAN

703, a 2 nd

704, and a 2 nd memory 705. The input stage of the 2 nd ECU701 is connected to the output stage of the

70, and the image of the

70 is transmitted from the 2 nd CAN

703 to the

20 via the 2

701. Further, the 2 nd ECU701 is connected to the

702, the 2 nd

704, and the 2 nd memory 705, respectively.

Next, adjustment of the display position of the

100 in the HUD1 having the configuration described above will be described with reference to fig. 5. Fig. 5 is a diagram showing a relationship between the viewpoint, the reflection position of the image light L on the

3, and the virtual image position.

In the HUD1, the following control is performed: the

700 detects the viewpoint using the image of the

70, and adjusts the display position of the

100 projected onto the

3 of the

2 by controlling the rotation angle (inclination angle) of the

43 in accordance with the detected viewpoint of the

5. In fig. 5, the rotational (tilting) position of the

43, the projection position of the

100 on the

3, and the position of the

100 as viewed from the viewpoint of the

5 are indicated by A, B, C, respectively, corresponding to the position A, B, C of the viewpoint of the

5.

The above control is realized, for example, by: the 2 nd CAN

703 of the

700 notifies the

20 of the viewpoint information, and the

20 rotates the

43. In this

700, acquisition of information from the

70 is performed under the control of the 2

701. In the

20, the acquisition of the vehicle information 9, the control of the

30, and the driving of the

43 are performed under the control of the 1

21. However, the present invention is not necessarily limited to these examples, and other types of devices may be provided.

The HUD1 is also characterized by using the image of the

70 in combination with the process of adjusting the virtual image position in accordance with the viewpoint of the

5 and the process of monitoring the amount of sunlight entering the HUD 1.

When the power of the HUD1 is turned on (S10/yes), the

70 starts imaging (S11), and outputs the imaged image to the

700. This image reflects the

52a (see fig. 15) of the image light L in the

52, and includes, as an object, the entire face including the eyes of the

5 or a part of the face reflected on the

52a of the image light L. When the near-infrared light reflected by the surface of the face of the

5 reaches a position different from the

52a in the

52, the region where the near-infrared light reaches is included in the angle of view of the

70, and the face image is captured.

The 2 nd ECU701 of the visual

700 acquires an image from the

70 and executes the visual point detection process (S20). The details of which will be described later.

The 2 nd ECU701 calculates a viewpoint movement amount (S21) which is a difference between the viewpoint position obtained in step S20 and the viewpoint position used when the display position of the

100 is determined from the current HUD1, and transmits the viewpoint movement amount to the

20. The details of which will be described later.

In the 2

212 captured at a standard brightness, for example, a brightness at which the

5 can drive without lighting the headlights without excessively dazzling, the peak value of the 2

222 indicating the distribution of the brightness values of the image is not large, and the brightness values are dispersed. The area of the 2 nd histogram 222 (a portion to which colors are added in the figure) indicates the total number of pixels of the image, and the areas of the 1

221 and the 3

223, which will be described later, are the same as the area of the 2

222.

On the other hand, the 1

221 showing the distribution of the luminance values of the 1

211 captured in a dark place has a large number of dark luminance values. The 3

223 showing the distribution of the luminance values of the 3

213 captured in a location where the luminance is too bright, that is, a location where the amount of solar light irradiated to the

52 is large, has a large number of pixels of bright luminance values.

Therefore, the 2 nd ECU701 obtains the luminance value of each image as an integrated value of (luminance value × number of degrees), and outputs the luminance value to the

20.

When the 1 st ECU21 of the

20 determines that the brightness value of the image obtained in step S30 is equal to or greater than the predetermined light-shielding threshold value (S40/yes), the

29 is used to start measurement of the elapsed time t from when the brightness value of the image becomes equal to or greater than the light-shielding threshold value (S41). When the elapsed time t is equal to or greater than the predetermined time threshold (S42/yes), the mirror adjustment unit 28 rotates the

43 so that the sunlight does not reach the image display device 30 (hereinafter referred to as "light shielding angle") (S43). At this point in time, the counting by the

29 may be ended.

Fig. 8 is a diagram showing a state in which the

43 is rotated to the light shielding angle.

A part of the sunlight Sb that has reached the

52 is reflected and enters the

70, and a part thereof passes through the

52 and reaches the

43. When the

43 is rotated at the light shielding angle, the sunlight Sb that has reached the

43 is reflected by the mirror surface of the

43 and is reflected in the lower direction of the

50, that is, in a direction different from the direction toward the

42.

Accordingly, the image light L is not irradiated toward the

52, and therefore the display of the

100 disappears, and the optical path through which the sunlight Sb incident from the

52 reaches the

30 via the

43 and the

42 can also be cut off. Further, the sunlight Sb incident from the

52 can be prevented from being reflected by the

43 and re-irradiated toward the

52 and irradiated to the

3.

On the other hand, in the case where the luminance value of the image is smaller than the light-shielding threshold (S40/no), the 1 st ECU21 causes the mirror adjustment section 28 to return (restore) the mirror surface of the

43 to the optical path of the video light L (S45) during the rotation of the

43 by the light-shielding angle, that is, in the case where the luminance value of the image is already equal to or greater than the light-shielding threshold and the mirror surface of the

43 is made to avoid the optical path of the video light L (S44/yes).

After step S45 is completed, or when the

43 is not rotating at the shading angle (S44/no), that is, when the mirror surface of the

43 is on the optical path of the video light L, or when the elapsed time t is less than the time threshold (S42/no), the 1 st ECU21 compares whether or not the movement amount of the viewpoint is equal to or greater than a predetermined movement amount threshold (S46).

When the movement amount of the viewpoint is equal to or greater than the movement amount threshold (S46/yes), 1 st ECU21 performs mirror adjustment processing for matching the virtual image position with the viewpoint with respect to mirror adjustment unit 28 (S47). More specifically, a signal for rotating the

43 in accordance with the viewpoint movement amount calculated in S21 is output from the mirror adjustment unit 28 to the

44 a. This allows the virtual image to be displayed in accordance with the position of the viewpoint detected by

700.

After the mirror adjustment process (S47) or when the movement amount of the viewpoint is smaller than the movement amount threshold (S46/no), the 1 st ECU21 performs distortion correction of the display object displayed as the

100 in the

25, and the display

26 displays the display object after the distortion correction on the

33. At the same time, ECU 1 21 causes light

24 to execute the lighting process of

31 and causes display

33 to emit video light L including the display object. The image light L is enlarged in the virtual image

40, projected to the

3, and incident to the eyes of the

5, thereby displaying the virtual image 100 (S48). If the power of the HUD1 is not off (S49/NO), the process returns to step S11, and the subsequent processes are repeated. When the power of the HUD1 becomes off (S49/yes), the virtual image display processing by the HUD1 is ended.

Fig. 9 is a diagram showing a 3-dimensional spatial coordinate system inside the

2.

Inside the

2, the

70 is fixedly disposed at a position where the face (viewpoint) of the

5 can be imaged, and inside the

10 in the present embodiment (see fig. 3). At this time, the

70 is disposed at the center in the 3-dimensional space coordinates inside the

2, and the x-axis is set to the longitudinal direction of the vehicle 2 (the traveling direction of the vehicle), the y-axis is set to the width direction of the vehicle, and the z-axis is set to the height (vertical) direction. Fig. 9 shows a state when this state is viewed from above. The

70 captures an image including the face (viewpoint) of the

5 from the front of the

5 in a 3-dimensional space inside the vehicle centered thereon. In fig. 9,

71 denotes an imaging range of the

70.

The 2 nd ECU701 detects the eyes (viewpoint) from the 2-dimensional camera image captured by the

70. Next, the 2 nd ECU701 obtains a straight line from the camera 70 (the origin of the 3-dimensional space) toward the detected eye (viewpoint) 5 of the driver 5 (i.e., connects the

70 and the viewpoint). This makes it possible to specify a straight line in the direction toward the eyes (viewpoint) of the

5 when viewed from the

70, i.e., the origin of the 3-dimensional space. In other words, when the 1 point (the position of the eye of the

5 in the above description) on the camera image (2 d) is specified from the relationship between the installation direction of the

70 and the angle of view, the straight line on the 3 d space connecting the

70 and the 1 point on the image can be obtained. However, it is not possible to define where the eye is located on a straight line.

Next, an intersection point between the straight line in 3 dimensions obtained in the above and a vertical plane (z-x plane) in 3 dimensions passing through the center of the seat (or the central axis of the steering wheel 8) is obtained, and the obtained intersection point is a viewpoint position of the eyes of the

5. A vertical plane (z-x plane) in 3 dimensions passing through the center of the seat (center axis of the steering wheel) is a z-x plane that is distant from the camera 70 (origin) to the center of the seat in the width direction (y axis) of the

2, and this distance can be set in advance when the

70 is disposed inside the

2 or can be determined by measurement.

That is, the 2 nd ECU701 obtains the coordinates (x) of the viewpoint of the

5 from the face of the

5 captured by the

70 by the viewpoint detection processing described above_d，y_d，z_d) And stored in the 2 nd

704. Then, the images of the

70 captured at the down-sampling cycle as described above are used for the viewpoint moving amount arithmetic processing (S21).

The

5 may tilt forward or move his head, and the viewpoint position may be displaced. Therefore, the 2 nd ECU701 estimates the orientation of the face of the

5 from the image captured by the

70, determines whether the face of the

5 is located at the center of the seat from the estimated orientation of the face, and performs position adjustment of the

43. Fig. 10A, 10B, and 10C are explanatory views of the amount of viewpoint movement accompanying the movement of the head of the driver.

As shown in fig. 10A, the orientation of the face of the driver 5 (the 3 directions of roll, pitch, and yaw, as indicated by the arrows in the figure) is estimated from the image captured by the

70, and when it is determined that the face is oriented toward the front of the vehicle, the viewpoint coordinates (x) of the

5 obtained as described above are used_d，y_d，z_d) The display position adjustment of the

100 based on the angle adjustment of the

43 is performed. As shown in fig. 10B and 10C, when the face of the

5 is oriented away from the front of the vehicle, the display position of the

100 is not adjusted by the angle adjustment of the

43. In the present embodiment, particularly, in order to suppress the display position of the

100 from frequently matching the fine movement of the head of the driver 5Instead, the 2 nd ECU701 obtains the previous viewpoint detection position (x)_dt，y_dt，z_dt) The viewpoint detecting position (x) at this time_dt+1，y_dt+1，z_dt+1) difference (Δ x_d，Δy_d，Δz_d) When Δ x_d、Δy_d、Δz_dIs a movement amount threshold value Δ x predetermined to determine that the head of the

5 is moved_dth、Δy_dth、Δz_dthWhen the above, will contain (Δ x)_d，Δy_d，Δz_d) The viewpoint moving amount information of (2) is outputted to the

20.

According to the present embodiment, since the viewpoint of the

5 is detected and the display position of the

100 is adjusted in accordance with the detection result, the visibility of the

100 can be improved.

Further, the

70 for viewpoint detection is provided in the visual field generated by the

10 when viewed from the

5, so that the aesthetic appearance in the

2 is improved.

Further, since the

70 captures the face of the

5 reflected on the

52, the face image can be captured substantially from the front, and the viewpoint detection can be performed with high accuracy.

The

70 can function as a monitoring camera for the amount of sunlight incident on the HUD1, and the number of components can be reduced as compared with a case where a monitoring member is separately prepared.

Further, since the

70 is disposed at a position avoiding the optical path of the video light L of the HUD1, even after the incident amount of sunlight becomes too large and the optical path of the video light L is shielded, the incident amount of sunlight can be monitored, and when the incident amount is smaller than the light shielding threshold, the optical path of the video light L can be restored again.

In addition, as the structure for blocking the optical path of the image light L in the above description, a structure is used in which the mirror surface of the

43 is made to avoid the optical path of the image light L (the mirror surface of the

43 is rotated at a blocking angle from the optical path of the image light L), but the structure is not limited thereto. Fig. 11 to 14 show a shutter structure as a light blocking structure for the image light L.

Fig. 11 is a schematic diagram showing the mounting position of the

306 in the HUD1 a. Fig. 12 is an enlarged explanatory view of the

300. Fig. 13 is a diagram showing a state where the

306 is in the light shielding position. Fig. 14 is a diagram showing a state where the

306 is at the escape position.

The HUD1a shown in fig. 11 includes a

300 for disposing or avoiding the

306 in front of the exit surface (surface on the

41 side) of the image light L in the

30. The

300 is connected to the

20 by a

61. The

20 controls the driving of the

300 so that the

306 is positioned at the light shielding position (see fig. 13) in step S43 and the

306 is positioned at the escape position (see fig. 14) in step S45.

As shown in fig. 12, the

300 includes a

306 and a mechanism for moving the

306, specifically, a

301, a

302, a

303, a

304, a

305, and a

307. The

301 is communicatively connected to the

20 via the

61. The

305 and the

307 are attached to the

50.

The

301 has a rotating shaft coupled to the

302, and one end of the

303 is coupled to the

302.

The other end of the

303 is held by a

305. A thread is cut on the surface of the

303.

304 retains

306. At a position opposite to the

303 in the

304, a screw groove is cut. The thread of the

303 engages with the thread groove of the

304.

The

307 is provided opposite to the

303 with the

306 interposed therebetween. A groove shape is provided in the

307 on the surface opposite to the

304. The end of the

304 facing the

307 is inserted into the groove of the

307, and the

304 and the

306 are prevented from wobbling when the

306 moves from the off position to the light blocking position or from the light blocking position to the off position, and can move stably.

When a forward rotation signal or a reverse rotation signal is sent from the

20 to the

301, the

301 rotates forward or in reverse in accordance therewith. When the rotation shaft of the

301 rotates in the forward direction or in the reverse direction, the

303 rotates in the forward direction or in the reverse direction via the

302. Then, the

304 moves from the escape position to the light shielding position or from the light shielding position to the escape position along the thread of the

303. The

306 moves from the escape position to the light-shielding position or from the light-shielding position to the escape position integrally with the

304. In this example, the

300 is disposed in front of the

30, but the

300 may be provided on the optical path of the image light L in the HUD1a, and is not limited to the front of the

30.

In the above description, although the mirror adjustment unit 28 has been described as driving the

44 in step S45, the process may be performed only by storing a flag indicating that the mirror surface is rotated at the shading angle. Further, when the virtual image position is controlled in step S47, the

43 may be restored at the same time. This can reduce the number of times of driving the

43.

In the above, when the virtual image display is performed in the immediately preceding process (S48) without turning off the virtual image display after rotating the

43 at the light-shielding angle in step S43, the

43 is rotated at the light-shielding angle while the virtual image display process is kept being performed. However, since the generation of the image light L after the

43 is rotated at the light-shielding angle is unnecessary regardless of the display of the

100, a process of turning off the virtual image display, for example, a process of turning off the

31 or a process of making the display object non-display in the

33 may be added after step S43. In this case, when the virtual image is displayed in the next step S48, the process of turning on the

31 or displaying the display object on the

33 is started again.

Fig. 15 is a view showing another embodiment in which the

52b is provided in the

52. In fig. 14, a

52b that reflects natural light (including near infrared light to visible light) is provided in a region of the

52 that is different from the

52a of the image light L. Then, the reflecting

52b reflects the natural light, which is reflected by the face surface of the

5 and reaches the

52 via the

3, toward the

70. The reflecting

52b may be an aluminum plate or a mirror, for example. This enables the

70 to more clearly capture the face image of the

5.

1. A head-up display that displays a virtual image in front of a vehicle, the head-up display comprising:

an image display device including a light source and a display element, for displaying a display object on the display element and emitting image light including the display object;

a virtual image optical system that enlarges and projects the image light toward the projection target member while changing an emission direction;

a frame body which accommodates the image display device and the virtual image optical system;

a frame opening portion provided in the frame so that the image light is emitted from the frame;

an antiglare shield covering the frame opening and transmitting the image light;

a camera that captures an image of a face area including eyes of a driver of the vehicle;

a viewpoint detection device that detects a viewpoint of the driver from an image captured by the camera; and

a main control device connected to the image display device, the virtual image optical system, and the viewpoint detection device,

the camera is provided outside the housing at a position avoiding an optical path of the image light emitted from the housing opening in a direction of imaging a region of the antiglare plate in which a face including the eyes of the driver is projected,

the main control device controls the virtual image optical system to adjust the emitting direction of the image light according to the viewpoint position of the driver detected by the viewpoint detection device.

2. The head-up display of claim 1,

the camera includes an image pickup element that detects near-infrared light,

an image including a near-infrared light image is output.

3. The head-up display of claim 1,

the camera includes an image pickup element that detects near infrared light to visible light,

the glare shield further includes a reflecting member that reflects natural light that is reflected by the surface of the driver's face and reaches the glare shield via the projected member, toward the camera, in a region of the glare shield that is different from the region in which the image light is emitted,

the camera detects the natural light reflected from the antiglare plate and takes a picture of the image.

4. The head-up display of claim 1,

the camera is disposed in such a direction that an optical axis of the camera is incident toward the center of the driver's eyepoint at an angle within an allowable range that can be regarded as horizontal with respect to a horizontal axis.

5. The head-up display of claim 1,

the head-up display further includes a light shielding member that opens and closes an optical path of the image light from the dazzle prevention plate toward the projected member,

the main control device is also connected to the shade member,

the camera is arranged outside the frame body according to a direction for shooting a region of at least a partial region of the emitting region of the image light in the anti-dazzle plate,

the main control device controls the light shielding member to close the optical path of the image light when the brightness value of the image captured by the camera is equal to or greater than a predetermined light shielding threshold value.

6. The heads-up display of claim 5,

the main control device controls the light shielding member to open the optical path of the image light when a brightness value of an image newly captured by the camera after the light shielding member is controlled to close the optical path of the image light is smaller than the light shielding threshold.

7. The heads-up display of claim 5,

the virtual image optical system includes a concave mirror that reflects the image light toward the projection member and a mirror driving unit that changes an orientation of a mirror surface of the concave mirror,

the main control device outputs a control signal for rotating the concave mirror to the mirror driving unit based on the viewpoint position of the driver detected by the viewpoint detecting device, and outputs a control signal for rotating the mirror surface of the concave mirror at an angle avoiding the optical path of the image light to the mirror driving unit when the luminance value of the image captured by the camera is equal to or greater than a predetermined light shielding threshold value.

8. The heads-up display of claim 5,

the light-shielding member is a shutter member,

the shutter member includes a shutter and a moving mechanism that moves the shutter to a retracted position and a light-shielding position,

the avoiding position is a position where the shutter is disposed so as to be offset from the optical path of the image light, and the light blocking position is a position where the shutter is disposed on the optical path of the image light.